Purification through sublimation is an integrated technique that mainly uses thermal energy to transform a mixed compound into two phases, including separated gas and liquid states, and gas and solid states. The technique may be adopted in processes for mixed compound systems consisting of proximate or common boiling points. Through the common boiling points the compounds are distilled by sublimating or extracted by distilling and sublimating to achieve purification and refinement.
The present methods for purification through sublimation generally use a sublimation apparatus to hold a powdered object to be sublimated and heat in a vacuum environment to sublimate the object to achieve the purpose of purification. As the object to be sublimated is formed in powders, it has a loose structure with a lot of voids formed in the object. The voids result in poor heat transfer effect. The effect is especially obvious in the vacuum environment.
Because of the loose structure of the structure of the object to be purified, the substance in a unit volume is limited. As a result, the resulting purified material after each sublimation process is small. To obtain a selected amount of purified material, many times of sublimation and purification processes have to be performed. During sublimation and purification processes; the door of the purification chamber has to be opened whenever the object of the purification is replaced. Every time the door of the purification chamber is opened, temperature must be lowered and gas has to be discharged. Once the object of the purification has been replaced, another gas discharge and heating have to be performed. The processes waste time and increase the possibility of lower quality of purification.
Moreover, the general methods for purification through sublimation have the purified material flowing in any direction after the sublimation was finished. They result in the purified material depositing in a scattered manner in every collecting section. Collecting the purified material also is time consuming.